83 911 Brake trouble!!!! I need Help!

83targa · 09-04-2008, 05:39 PM

Greetings to all. I purchased a 1983 911 targa from a friend a month ago. During the 16 plus years he owned the car it was troubled with problems and spent most of the time in the garage. I love a challenge so I bought the car from him. When I got it the brakes did not work ....at all. The pedal went right to the floor. I found one of the lines from the reservoir had a leak. I changed it and flushed the brake system. I spent a whole day trying to get them to build up pressure but no luck. They will apply pressure to the pads but not pressure to the pedal. I checked some forums and the repair manual and all pointed to the Master Cylinder. I replaced it with one purchased on-line. Still no luck and several folks said it was more than likely a bad rebuilt unit. SO I replaced it with a brand new ATE $220 thank you very much. I have tried using the $5 low pressure bleeder and still am not getting pressure to build on the brake pedal. If you pump 5-6 times rapidly you will get very little pressure but then if you pump slowly it goes right to the floor. There is not a drop of fluid anywhere on the ground under the car. I am getting beat on this one and could use some help.

Jubbie · 09-04-2008, 05:47 PM

Brake booster?

Mine doesn't have one and I am not sure they fail that way, but it is the only other thing that may be in common with the failure. I know in bleeding my Dad's long hood that you had to let it sit over night between pedal pumping bleeding to let it statically bleed itself, but there again, I always got pressure.

Good luck

tonythetarga · 09-04-2008, 05:52 PM

What is the bleeding sequence you are using? You want to start the furthest from the m/c, which is right rear, then left rear, then right front and left front. If that is the way you've been doing it, then have a look at the calipers and make sure the bleed screws are at the top of each caliper. They can be mistakenly put on incorrectly, left to right and be upside down.

Are you having to add fluid? If you see no drips but are losing fluid, you could be pumping into the booster. The other issue is you could have a bad booster diaphram and not be building pressure.

83targa · 09-04-2008, 06:01 PM

thanks, The bleed screws in the rear are on top BUT the front are on the bottom. Could this be causing a problem?

tonythetarga · 04:13 AM

Quote:

Originally Posted by 83targa

thanks, The bleed screws in the rear are on top BUT the front are on the bottom. Could this be causing a problem?

Air wants to go up! The bubbles are trapped and the fluid continues to pour out. Take the fronts off and switch them right to left. Rebleed. If there are no leaks and with a new m/c, you should have brakes that will stop the car.
What fluid are you using?

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by 83targa

thanks, The bleed screws in the rear are on top BUT the front are on the bottom. Could this be causing a problem?

it's certainly part of the problem. There is absolutly no way to bleeed a caliper which has the bleeds on the bottom.

The fronts have been mounted upside down!

83targa · 09-04-2008, 06:17 PM

That's a breath of fresh air.THANKS. I will give that a go first thing in the morning. I am using a super duty DOT 4 made in Germany. Fluid was purchased fro BAP-Gieon. Any better recomendation on the fluid as I am sure I will go through another large jug when I re bleed the system.
Like I said the car has had issues and I am sure I will be on this site....ALOT!!!!! I want to get the car moving then work on the other issues.

Bill Verburg · Bill Verburg's Garage

For street use ATE 200(yellow or blue) or Castrol LMA are going to be fine

83targa · 09-05-2008, 11:17 AM

That was it! Thanks so much for the help on this one!

tonythetarga · 09-05-2008, 11:32 AM

OK, now that this problem is out of the way, time to post a picture of the car. It is also helpful to identify where you are (as in the location under your user name). You never know, you may actually find people near you that could help out or also find events in your area you might be interested in attending. Pretty soon you'll find out about DE's and then you're done for...slippery slope here we come!

MBAtarga · 09-05-2008, 01:22 PM

I'm impressed with you guys! This car has been sitting/not driven for who knows how long with "bad brakes", and tonythetarger nails the cause within 13 minutes of the original post.

Oh - and 83targa - along with tony's suggestion on the location, consider adding your first name to your signature.

Paul Crowther · 09-06-2008, 04:26 AM

Mark,
You will be amazed at the years of amassed experience on this board. If you ever are puzzled by something you should always consider throwing the question out to the crew here.

Nowhere else will you find so much Porsche-specific knowledge at your fingertips!

Paul